Kuo, Y., "Multi-Notch Filter (MNF) Algorithm for Automotive Radio-Frequency (RF) Signal Processing and Applications," SAE Int. J. Passeng. Cars – Electron. Electr. Syst. 7(2):440-448, 2014, doi:10.4271/2014-01-0264.
The radio frequency (RF) filter is a well-known technique that has been used in communication systems for a long time. It is able to limit the selected band from receiving signals or transmitting signals. The filter can be a low-pass filter, high-pass filter, band-pass filter, and notch-filter or combined filters. This paper presents the unique Multi-Notch Filter (MNF) which takes advantages of the properties of “sinusoid wave” and “linear functions”. Since an automotive receiver is operated in noisy environments, this method is particularly useful to improve an automotive receiver's performance at the input stage when it immediately processes RF signals from an antenna. This type of filer can easily be implemented into an automotive receiver to notch out more unwanted frequency(s), such as harmonic frequencies, motor noise and very low frequencies (power line noise), which will result in better noise immunity for mobile receivers against noisy environments. In the following sections we will discuss; key criteria for good receiver design, the background theory of this unique multi-notch filter, the architecture of this multi-notch filter, and examples of this multi-notch filter's implementation for receiver.